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1.
PLoS One ; 16(7): e0254687, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270609

RESUMO

The relative age effect (RAE) has primarily been investigated in male athletes involved in popular sports and high-level competitions. However, occurrence of RAE in other types of sports at the grassroots level, particularly in female athletes, is less well-studied. Thus, we examined the RAE in a large cohort of young athletes who participated in all competitive sports in Bizkaia, Spain, according to gender and specificity of the sport. The birth dates of 38,381 participants (65.1% males and 34.9% females) aged 9-14 years old in 37 competitive sports were analyzed. Birth dates were divided into four birth-quarters and compared to those of all children born in the same period using a χ2 goodness-of-fit test and standardized residuals. The effect size Cramer's V was measured, and odds ratio and 95% confidence intervals were calculated to determine the odds of athletes born in January playing in the highest leagues. In the total sample, in boys RAE was evident in football, but only in higher-competition leagues (p<0.001, large effect size). In girls, RAE was evident in the most popular team sports: basketball (p<0.001, large effect size in basketball 1st league), handball and football (p<0.05, both small effect sizes). Players born in January were 3.23- and 2.89-times more likely to play in the 1st leagues than those born in December, for boys (football) and girls (basketball) respectively. In the overall analysis and in the remaining sports, presence of RAE was negligible. Therefore, the date of birth does not seem to be a constraint to participating in most sports in Bizkaia. The potential mechanisms for RAE are multifactorial and complex, yet a combination of factors, such as the popularity of a sport and the depth of competition, physicality and social influences may be involved. We discuss these mechanisms and potential measures to mitigate RAE.


Assuntos
Desempenho Atlético/estatística & dados numéricos , Adolescente , Fatores Etários , Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Criança , Interpretação Estatística de Dados , Feminino , Futebol Americano/fisiologia , Humanos , Masculino
2.
J Sports Sci Med ; 20(2): 317-327, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34211325

RESUMO

This study aimed to compare the between-session reliability of performance and asymmetry variables between unilateral and bilateral standing broad jumps (SBJ). Twenty-four amateur basketball players (12 males and females) completed two identical sessions which consisted of four unilateral SBJs (two with each leg) and two bilateral SBJs. Mean and peak values of force, velocity and power, and impulse were obtained separately for each leg using a dual force platform. Inter-limb asymmetries were computed using the standard percentage difference for the unilateral SBJ, and the bilateral asymmetry index-1 for the bilateral SBJ. All performance variables generally presented an acceptable absolute reliability for both SBJs (CV range = 3.65-9.81%) with some exceptions for mean force, mean power, and peak power obtained with both legs (CV range = 10.00-15.46%). Three out of 14 variables were obtained with higher reliability during the unilateral SBJ (CVratio ≥ 1.18), and 5 out of 14 during the bilateral SBJ (CVratio ≥ 1.27). Asymmetry variables always showed unacceptable reliability (ICCrange = -0.40 to 0.58), and slight to fair levels of agreement in their direction (Kappa range = -0.12 to 0.40) except for unilateral SBJ peak velocity [Kappa = 0.52] and bilateral SBJ peak power [Kappa = 0.51]) that showed moderate agreement for both SBJs. These results highlight that single-leg performance variables can be generally obtained with acceptable reliability regardless of the SBJ variant, but the reliability of the inter-limb asymmetries in the conditions examined in the present study is unacceptable to track individual changes in performance.


Assuntos
Teste de Esforço/métodos , Perna (Membro)/fisiologia , Exercício Pliométrico , Adolescente , Basquetebol/fisiologia , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Posição Ortostática , Adulto Jovem
3.
J Sports Sci Med ; 20(2): 365-372, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34211330

RESUMO

The ideal timing to implement anterior cruciate ligament injury prevention programs with respect to maturation is unclear. The purpose of this study was to investigate the effects of an injury prevention program on knee mechanics in early-, late-, and post-pubertal females. In the study, 178 adolescent female basketball players were assigned to six groups: early-pubertal training, early-pubertal control, late-pubertal training, and late-pubertal control, post-pubertal training, and post-pubertal control. The training groups performed an injury prevention program for six months. Medial knee displacement, knee flexion range of motion, and the probability of high knee abduction moment were assessed before and after the training period. After the six-month training period, medial knee displacement was significantly increased in the early-pubertal control group whereas it was unchanged in the early-pubertal training group. Knee flexion range of motion was significantly decreased in the early-pubertal control group whereas it did not change in the early-pubertal training group. The probability of high knee abduction moment was increased in the early-pubertal control group whereas it was unchanged in the earl-pubertal training group. The probability of high knee abduction moment was also decreased in the post-pubertal training group whereas it did not change in the post-pubertal control group. The program limited the development of high-risk movement patterns associated with maturation in early puberty while improving the knee mechanics in post-pubertal adolescents. Therefore, an injury prevention program should be initiated in early puberty and continue through the post-puberty years.


Assuntos
Lesões do Ligamento Cruzado Anterior/prevenção & controle , Condicionamento Físico Humano/métodos , Puberdade , Adolescente , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Basquetebol/lesões , Basquetebol/fisiologia , Fenômenos Biomecânicos , Criança , Feminino , Humanos , Joelho/fisiologia , Movimento , Desenvolvimento de Programas , Amplitude de Movimento Articular , Fatores de Risco
4.
J Sports Sci Med ; 20(3): 508-515, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34267591

RESUMO

The aim of this study was to investigate the role of release parameter changes within individuals (intra-individual) on basketball shooting performance across both free throws and three-point shots, and identify whether any velocity dependence exists. Twelve male basketball players were recorded shooting seventy-five three-point shots (6.75 m) and fifty free throws (4.19 m). Ball release parameters were estimated by combining an analytic trajectory model including drag, a least squares estimator, and gradient-based release distance compensation. Intra-individual release velocity standard deviations (SD) were found to be significantly smaller across all distances ([0.05-0.13 m/s] when compared to statistics reported by other studies [0.2-0.8 m/s]). Despite an increase in lower body motion and a 24% increase in release velocity (p < 0.001) as shooting distance increased, no increases in intra-individual release velocity or angle SD were observed indicating velocity-dependent changes in release parameters were absent. Shooting performance was found to be strongly correlated to the release velocity SD (r = -0.96, p < 0.001, for three-point shots, and r = -0.88, p < 0.001, for free throws). Release angle SD (1.2 ± 0.24 deg, for three-point shots, and 1.3 ± 0.26 deg, for free throws) showed no increase with distance and unrelated to performance. These findings suggest that velocity-dependent factors have minimal contribution to shooting strategies and an individual's ability to control release velocity at any distance is a primary factor in determining their shooting performance.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Destreza Motora/fisiologia , Adulto , Fenômenos Biomecânicos , Cotovelo/fisiologia , Humanos , Masculino , Propriocepção/fisiologia , Estudos de Tempo e Movimento , Punho/fisiologia , Adulto Jovem
5.
Rev. bras. med. esporte ; 27(2): 225-230, Apr.-June 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1280074

RESUMO

ABSTRACT Introduction: Among the main challenges faced by coaches of team sports are to create an environment and conditions that will enable players to reach their optimal level of physical performance at the start of the competitive season, and to maintain this level throughout the season. Objective: The purpose of this study was to assess the effects of six weeks of additional training with 3-against-3 (3v3) small-sided games (SSG) on the physical performance of elite nonstarter basketball players. Methods: Eleven professional basketball players (five starters and six nonstarters) performed the same training program throughout the regular season, with the only difference that after each game, the starters (S) performed low intensity shooting drills while the nonstarters (NS) performed half-court 3v3 SSG. At the start and end of the six-week period, the athletes were assessed for muscle power, speed, agility and aerobic power. Two-way analysis of variance and effect sizes were used. Magnitude-based inferential analyses were used to complement the parametric tests. Results: After the six weeks, the S and NS showed improvement (p<0.05) in the squat jump (S=5.8% and NS=7.1%), counter movement jump (S=3.7% and NS=3.6%), 20m-sprint (S=3.4% and NS=2.0%), agility T test (S=3.6% and NS=3.1%) and Yo-yo intermittent recovery (S=5.2% and NS=2.5%). No differences were found between groups and moments. The effect sizes showed moderate effect on agility and little effect on jumping ability, for both groups; moderate, for S, and little, for NS, on speed and aerobic conditioning. Magnitude-based inferences indicated that S were likely to outperform NS in terms of improvement in 20-m sprint ability and possibly also in agility. In regard to the other physical performance variables, the analyses of magnitude-based inferences were inconclusive. Conclusions: The results of this study showed that 3v3 SSG in the short-term on half-court, as an additional training routine for NS, can bring positive results for the physical performance for these players. Level of evidence II; Investigating the Results of Treatment.


RESUMEN Introducción: Uno de los principales desafíos de los entrenadores de deportes colectivos es crear ambiente y las condiciones que permitan a los jugadores alcanzar su nivel ideal de desempeño físico al inicio de la temporada competitiva y mantener ese nivel a lo largo de la temporada. Objetivos: El objetivo de este estudio fue evaluar los efectos de seis semanas de entrenamiento adicional con juegos reducidos (JR) 3 contra 3 (3x3) sobre el desempeño físico de jugadores suplentes del baloncesto de élite. Métodos: Once jugadores profesionales (cinco titulares y seis suplentes) realizaron el mismo programa de entrenamiento durante la temporada regular, con la única diferencia de que, después de cada partido, los titulares (T) realizaban ejercicios de lanzamiento de baja intensidad, mientras que los suplentes (S) realizaban JR 3x3 en media cancha. Al inicio y al final de cada período de seis semanas los atletas fueron evaluados en cuanto a la potencia muscular, velocidad, agilidad y potencia aeróbica. Fueron usados análisis de variancia y tamaños de efecto de dos vías. Fueron usados análisis inferenciales basados en magnitud para complementar los tests paramétricos. Resultados: Después de seis semanas, el grupo T y el S mostraron mejora (p <0,05) en el salto con agachamiento (T = 5,8% y S = 7,1%), salto contramovimiento (T = 3,7% y S = 3,6%), sprint de 20 metros (T = 3,4% y S = 2,0%), test T de agilidad (T = 3,6% y S = 3,1%) y el test de recuperación intermitente Yo-yo (T = 5,2% y S = 2,5%). No fueron encontradas diferencias entre grupos y momentos. Los tamaños de efecto mostraron efecto moderado en la agilidad y pequeño efecto en la capacidad de salto para ambos grupos; efecto moderado para el grupo T y pequeño para el S, en la velocidad y acondicionamiento aeróbico. Las inferencias basadas en la magnitud indicaron que el grupo T probablemente superaría al grupo S en términos de mejora de la habilidad de sprint de 20 metros y posiblemente también en agilidad. El análisis de las inferencias basadas en magnitud no fue concluyente con relación a las otras variables. Conclusiones: Los resultados de este estudio mostraron que JR 3x3 en media cancha como entrenamiento adicional para el grupo S puede ser positivo para el desempeño físico de esos jugadores. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento .


RESUMO Introdução: Um dos principais desafios dos treinadores de esportes coletivos é criar ambiente e as condições que permitam aos jogadores atingir seu nível ideal de desempenho físico no início da temporada competitiva e manter esse nível ao longo da temporada. Objetivos: O objetivo deste estudo foi avaliar os efeitos de seis semanas de treinamento adicional com jogo reduzido (JR) 3 contra 3 (3x3) sobre o desempenho físico de jogadores reservas do basquetebol de elite. Métodos: Onze jogadores profissionais de basquetebol (cinco titulares e seis reservas) realizaram o mesmo programa de treinamento durante a temporada regular, com a única diferença de que, depois de cada jogo, os titulares (T) realizavam exercícios de arremesso de baixa intensidade, enquanto os reservas (R) realizavam JR 3x3 em meia quadra. No início e no final do período de seis semanas, os atletas foram avaliados quanto à potência muscular, velocidade, agilidade e potência aeróbica. Foram usadas análises de variância e tamanhos de efeito de duas vias. As análises inferenciais baseadas em magnitude foram usadas para complementar os testes paramétricos. Resultados: Depois das seis semanas, o grupo T e o R mostraram melhora (p < 0,05) no salto com agachamento (T = 5,8% e R = 7,1%), salto contramovimento (T = 3,7% e R = 3,6%), sprint de 20 metros (T = 3,4% e R = 2,0%), teste T de agilidade (T = 3,6% e R = 3,1%) e o teste de recuperação intermitente Yo-yo (T = 5,2% e R = 2,5%). Não foram encontradas diferenças entre grupos e momentos. Os tamanhos de efeito mostraram efeito moderado na agilidade e pequeno efeito na capacidade de salto para ambos os grupos; efeito moderado para o grupo T e pequeno para o R na velocidade e condicionamento aeróbico. Inferências baseadas na magnitude indicaram que o grupo T provavelmente superaria o grupo R em termos de melhora da habilidade de sprint de 20 m e possivelmente também em agilidade. A análise das inferências baseadas em magnitude foi inconclusiva em relação às outras variáveis. Conclusões: Os resultados deste estudo mostraram que o JR 3x3 em meia quadra como treinamento adicional para o grupo R pode ser positivo para o desempenho físico desses jogadores. Nível de evidência II; Estudos terapêuticos - Investigação dos resultados do tratamento .


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Basquetebol/fisiologia , Desempenho Atlético/fisiologia , Condicionamento Físico Humano/métodos , Desempenho Físico Funcional , Teste de Esforço
6.
J Sports Med Phys Fitness ; 61(6): 771-778, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34110118

RESUMO

BACKGROUND: Speed and throw ball in basketball players are determinant skills for basketball performance. The purpose of this study was to determinate the relationship between speed and throw the ball with jump capacity and body composition in university basketball players. METHODS: A comparative descriptive study with transversal design and a quantitative approach was performed. Seventeen male University basketball players (age = 23.60±3.45 years, height = 180.41±7.99 cm and Body Mass = 86.48±20.07 Kg) completed the following test: throwing the ball (m/s), handgrip strength (kg), speed 5-20 m (i.e., with and without the ball), jumping and reactive strength. Likewise, anthropometric variables and body composition were evaluated. RESULTS: A very high correlation was found between the throw ball and the skeletal muscle mass (r=0.810, P<0.001) dominant handgrip strength (r=0.709, P<0.001) and non-dominant handgrip strength (r=0.610, P<0.01). The throw ball reported association with skeletal muscle mass (r2=0.67, P<0.001, 67% of the variance). Significant differences were found in speed with and without the ball at 10 m (P=0.003, ES=-0.854), 15 m (P=<001, ES=-1.548) and 20 m (P=<001, ES=-1.644). The speed of displacement without ball correlated high with the countermovement jump (CMJ) (r=-0.530, P≤0.05) Abalakov (r=-0.586, P≤0.05) and Drop Jump (DJ) (r=-0.685, P≤0.01) in the first 5 m. CONCLUSIONS: The speed and throwing of the ball are associated with jumping capacity and skeletal muscle mass. Therefore, it is necessary to work these capacities in the university basketball player to improve performance.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Adulto , Composição Corporal , Força da Mão/fisiologia , Humanos , Masculino , Músculo Esquelético/fisiologia , Universidades , Adulto Jovem
7.
PLoS One ; 16(5): e0251117, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33979374

RESUMO

In many kinds of sports, deceptive actions are frequently used to hamper the anticipation of an opponent. The head fake in basketball is often applied to deceive an observer regarding the direction of a pass. To perform a head fake, a basketball player turns the head in one direction, but passes the ball to the opposite direction. Several studies showed that reactions to passes with head fakes are slower and more error-prone than to passes without head fakes (head-fake effect). The aim of a basketball player is to produce a head-fake effect for as large as possible in the opponent. The question if the timing of the deceptive action influences the size of the head-fake effect has not yet been examined systematically. The present study investigated if the head-fake effect depends on the temporal lag between the head turn and the passing movement. To this end, the stimulus onset asynchrony between head turn, and pass was varied between 0 and 800 ms. The results showed the largest effect when the head turn precedes the pass by 300 ms. This result can be explained better by facilitating the processing of passes without head fake than by making it more difficult to process passes with a head fake. This result is discussed regarding practical implications and conclusions about the underlying mechanism of the head-fake effect in basketball are drawn.


Assuntos
Basquetebol/fisiologia , Basquetebol/psicologia , Decepção , Desempenho Atlético/fisiologia , Cabeça/fisiologia , Movimentos da Cabeça/fisiologia , Humanos , Masculino , Tempo de Reação , Esportes/fisiologia
8.
J Sports Sci Med ; 20(2): 188-196, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33948096

RESUMO

Missing data can influence calculations of accumulated athlete workload. The objectives were to identify the best single imputation methods and examine workload trends using multiple imputation. External (jumps per hour) and internal (rating of perceived exertion; RPE) workload were recorded for 93 (45 females, 48 males) high school basketball players throughout a season. Recorded data were simulated as missing and imputed using ten imputation methods based on the context of the individual, team and session. Both single imputation and machine learning methods were used to impute the simulated missing data. The difference between the imputed data and the actual workload values was computed as root mean squared error (RMSE). A generalized estimating equation determined the effect of imputation method on RMSE. Multiple imputation of the original dataset, with all known and actual missing workload data, was used to examine trends in longitudinal workload data. Following multiple imputation, a Pearson correlation evaluated the longitudinal association between jump count and sRPE over the season. A single imputation method based on the specific context of the session for which data are missing (team mean) was only outperformed by methods that combine information about the session and the individual (machine learning models). There was a significant and strong association between jump count and sRPE in the original data and imputed datasets using multiple imputation. The amount and nature of the missing data should be considered when choosing a method for single imputation of workload data in youth basketball. Multiple imputation using several predictor variables in a regression model can be used for analyses where workload is accumulated across an entire season.


Assuntos
Basquetebol/fisiologia , Interpretação Estatística de Dados , Condicionamento Físico Humano/fisiologia , Adolescente , Feminino , Humanos , Estudos Longitudinais , Aprendizado de Máquina , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Carga de Trabalho
9.
Sci Rep ; 11(1): 7489, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33820920

RESUMO

This study attempts to analyze the relationship between free-throw efficiency and the time of arm muscle activation in players from 3 basketball teams with different levels of experience was investigated. During the experiment each player made 20 free throws during which the activation time of his right and left biceps and triceps brachii muscles were measured with the use of surface electromyography and high-speed cameras. Significant differences in muscle activation time (t) during a free throw were found between the groups of basketball players (p = 0.038) (novices: t = 0.664 ± 0.225 s, intermediate-level players: t = 1.15 ± 0.146 s, experts: t = 1.01 ± 0.388 s). In the right triceps brachii muscle in expert basketball players the coefficient of variation (CV) amounted to 44.60% at 81% efficiency, and in novices to 27.12% at 53% efficiency. The time of arm muscle activation during a free throw and its fluctuations vary along with the training experience of basketball players. In all studied groups of players, the variability of muscle activation time in accurate free throws is greater than in inaccurate free throws. Free-throw speed is irrelevant for free-throw efficiency.


Assuntos
Basquetebol/fisiologia , Músculos/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
10.
Scand J Med Sci Sports ; 31(8): 1699-1707, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33908068

RESUMO

Weaker hamstrings muscular forces and lower ratio of the hamstrings/quadriceps muscular forces in female athletes have been identified as modifiable risk factors for anterior cruciate ligament (ACL) injuries. However, sex differences in athletes' ability to react to visual cues (Choice Visual-Motor Reaction Time: VMRT) and to generate knee muscular forces (rate of force development: RFD) immediately following the visual cues were largely unknown. Therefore, the purpose of the study was to examine sex differences in Choice VMRT and RFD. A total of 50 high school basketball athletes (26F/24 M) participated in the study. Subjects sat in the knee dynamometer chair with their knee secured at 70° of knee flexion and performed knee extension or flexion maximum voluntary isometric contractions immediately after they saw the visual cue: "UP" or "DOWN" arrows, respectively. Choice VMRT was defined as the time between the visual cue and the initiation of muscular force development (>5Newtons). RFD was calculated by dividing the changes in forces over the changes in time at four time points (0-50/100/150/200 ms). Peak muscular forces and RFD were normalized to their body mass. Average of three trials in each direction (flexion and extension) in each leg was used for statistical analyses. Females had significantly slower Choice VMRT (p < 0.001-0.027) and lower knee extension RFD at 100 ms (p = 0.005). In addition, females had significantly higher knee flexion/extension ratio than males in late RFD (150 ms and 200 ms) (p < 0.004). The current study has provided additional sensorimotor characteristics of athletes and sexes in addition to their knee muscular characteristics.


Assuntos
Basquetebol/fisiologia , Músculos Isquiossurais/fisiologia , Articulação do Joelho/fisiologia , Força Muscular/fisiologia , Músculo Quadríceps/fisiologia , Tempo de Reação/fisiologia , Adolescente , Feminino , Humanos , Contração Isométrica , Masculino , Fatores Sexuais
11.
PLoS One ; 16(4): e0249739, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33831106

RESUMO

The aim of this study was analyze the effect of playing against biological matched and un-matched opposition, on physical performance and spatial exploration behavior of youth basketball players. Thirty under-14 to 16 basketball players were assigned to different teams according to maturity status (Pre-, Mid-, and Post-Peak Height Velocity [PHV]), and participated in basketball matches against matched (same maturity status), and un-matched (different maturity status) opposition. Maturity status was estimated considering the percentage of predicted adult height. Workload data was collected via inertial devices (IMUs) and Ultra-Wide Band (UWB)-based system. Heart rate was recorded with individual HR monitors. The Pre-PHV performed significantly more accelerations and decelerations and explored more space against matched opposition. Against un-matched opposition, the Pre-PHV presented higher average speed, body impacts, and Player Load. Both Mid- and Post-PHV covered more distance against matched opposition than against Pre-PHV. Games against Pre-PHV involved lower distance covered, average speed, Player Load, and higher accelerations and decelerations, than against Mid- and Post-PHV. The Pre-PHV athletes performed a higher number of accelerations and decelerations comparing to the Mid and Post-PHV players. Also, a significant interaction effect (group x time) was found in distance covered, average speed, body impacts, and Player Load. The type of opposition influenced physical performance and spatial exploration behavior during basketball matches, particularly of less-mature players. Based on present findings, practitioners can select the most suitable game format, considering the physical, technical, tactical, and psychological development needs, individualizing training stimulus.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Comportamento Exploratório/fisiologia , Comportamento Espacial/fisiologia , Aceleração , Adolescente , Atletas , Criança , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Desempenho Físico Funcional , Corrida/fisiologia , Carga de Trabalho
12.
PLoS One ; 16(4): e0249679, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33826642

RESUMO

The aim of this study was to assess the differences in movement intensity demands between training activities and competition match-play in elite netball. Twelve elite female netballers (mean ± SD, age = 25.9 ± 5.1 years; height = 178.6 ± 8.9 cm, body mass = 71.1 ± 7.1 kg) competing in Australia's premier domestic netball competition participated. Data were collected across the season from all pre-season training sessions (n = 29), pre-season practice matches (n = 8), in-season training sessions (n = 21), in-season practice matches (n = 5), and competition matches (n = 15). Linear mixed-effects models assessed differences in PlayerLoad™ per minute and metreage per minute between activity types (Specialist, Skill Drills, Set-piece, Match Scenarios, Practice Match-play, and Competition Match-play) for positional groupings (Defenders, Midcourters, and Goalers). Competition Match-play resulted in higher (p < 0.05) PlayerLoad™ than all training activity types, with the largest magnitudes of difference between Specialist-Competition (d = 0.44-0.59; small to medium) and Skill Drills-Competition (d = 0.35-0.63; small to medium) for all positional groups. The smallest difference was found between Match Scenarios-Competition (d = 0.12-0.20; trivial to small) and Practice Match-play-Competition (d = 0.12-0.14; trivial). Competition Match-play also resulted in higher (p < 0.05) metreage per minute than Specialist (d = 0.23-0.53; small to medium), Skill Drills (d = 0.19-0.61; trivial to medium) and Set-piece (d = 0.05-0.31; trivial to small). Training activity demands in order of least to most similar to competition were specialist, skill drills, set-piece, match scenarios, and practice match-play. We provide data that enables coaches and physical preparation staff to incorporate progressions into their training session designs that can replicate the movement intensity demands of competition in training.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Comportamento Competitivo/fisiologia , Movimento/fisiologia , Acelerometria/métodos , Adulto , Feminino , Humanos , Condicionamento Físico Humano/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Ensino
13.
Int J Sports Med ; 42(11): 994-1003, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33621996

RESUMO

Basketball is characterized by high-intensity episodes predominantly reliant on anaerobic metabolism. The force-velocity test enables individual determination of an optimal braking force and emerged as appropriate to estimate optimal peak power. It has rarely been used in youth basketball. This study aimed to examine the contribution of body size, composition, and biological maturation to interindividual variation in force-velocity test output among pre-pubertal basketball players. The sample consisted of 64 male participants (8.4-12.3 years). Stature, sitting height, body mass and two skinfolds were measured, and leg length estimated. Fat-free mass and lower limb volume were estimated from anthropometry. Age at peak height velocity was predicted from maturity offset. Optimal peak power was correlated with all body size descriptors (correlation: 0.541-0.700). Simple allometric models explained 30-47% of inter-individual variance, with fat-free mass being the best predictor of performance. Whole-body fat-free mass (as a surrogate for active muscle mass) plus the indicator of maturation emerged as the best proportional allometric model (53% explained variance). Even at pre-pubertal ages, the interpretation of the force-velocity test requires assessing the metabolically active component of body mass.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Composição Corporal , Antropometria , Atletas , Tamanho Corporal , Criança , Teste de Esforço , Humanos , Extremidade Inferior , Masculino
14.
J Sports Sci ; 39(sup1): 116-124, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33530850

RESUMO

Pacing places a high demand on intellectual functioning and has been found useful for classification of athletes with intellectual impairments (II). This may also be true in open-loop sports like basketball. The current study aimed to investigate the pacing behaviour of basketball players with and without II. Using time-motion analysis, the activity of elite basketball players with II (n = 37) and amateur players without II (n = 34) was coded into four movement categories over eight periods of each game: standing, walking, running and jumping. Following two-way ANOVA, an effect of group showed differences between groups in duration and frequency of the movement categories within each period of the games. Additionally, an effect of time suggested that players in both groups paced their performances. However, no interaction was found, indicating that pacing may not be different between groups. In conclusion, the results suggest that due to the dynamic nature of basketball, the included players paced more intuitively by responding to environmental cues and using less deliberate planning. The players with II demonstrated slower games, which may be due to an impaired ability to make quick moment-to-moment deliberate decisions. These skills should be further studied in the context of evidence-based classification.


Assuntos
Desempenho Atlético/classificação , Basquetebol/classificação , Deficiência Intelectual/classificação , Paratletas/classificação , Esportes para Pessoas com Deficiência/classificação , Análise de Variância , Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Basquetebol/fisiologia , Tomada de Decisões , Metabolismo Energético/fisiologia , Humanos , Deficiência Intelectual/fisiopatologia , Deficiência Intelectual/psicologia , Movimento/fisiologia , Paratletas/psicologia , Reprodutibilidade dos Testes , Corrida/fisiologia , Esportes para Pessoas com Deficiência/fisiologia , Posição Ortostática , Esportes de Equipe , Estudos de Tempo e Movimento , Gravação em Vídeo , Caminhada/fisiologia
15.
J Sports Sci ; 39(12): 1386-1394, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33459193

RESUMO

This study examined the effects of shear reduction shoes on braking and propulsion ground reaction forces (GRFs), free moments, and joint moments when cutting towards different directions. Fifteen male university basketball players performed sidestep cutting towards 45°, 90° and 135° directions with maximum-effort in shear reduction and control shoes. Two-way (angle x shoe) ANOVAs with repeated measures were performed to determine the interaction and main effects of cutting angle and shoe for all tested variables. Results showed that cutting angles had significant influence on most of the variables, except for the peak-free moment, peak ankle eversion moment and maximum loading rate of resultant shear GRF. The shear reduction shoes significantly delayed the timing to the first peaks of vertical and resultant shear GRFs compared with the control shoes. During propulsion, the shear reduction shoes generated smaller peak propulsion resultant shear and vertical ground reaction forces. Additionally, the shear reduction shoes did not induce distinct frontal and transverse moments at the ankle and knee joints compared with the control shoes. These results suggest that the application of shear reduction structure could be beneficial to attenuate vertical and shear impact peaks, offering additional insights to reduce shear-related injuries.


Assuntos
Articulação do Tornozelo/fisiologia , Basquetebol/fisiologia , Desenho de Equipamento , Articulação do Joelho/fisiologia , Destreza Motora/fisiologia , Sapatos , Fenômenos Biomecânicos , Humanos , Masculino , Adulto Jovem
16.
PLoS One ; 16(1): e0245277, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33411844

RESUMO

This study was performed aimed at comparing multidirectional bilateral and unilateral jump performance and passive range of motion (ROM) of lower limbs between soccer and basketball young players and evaluating associations between inter-limb ROM asymmetry and bilateral jump performance. A total of 67 young male athletes participated in this study, who were classified as soccer (n = 40; 15.55 ± 1.5 y; 1.76 ± 0.12 m; 58.15 ± 10.82 kg; 19.84 ± 2.98 kg·m2) and basketball (n = 27; 15.7 ± 1.66 y; 1.76 ± 0.12 m; 62.33 ± 16.57 kg; 19.84 ± 2.98 kg·m2) players. Participants were asked to perform bilateral and unilateral multidirectional jumps, and passive ROM of hip (flexion, extension and abduction), knee (flexion) and ankle (dorsiflexion) joints was also assessed. Significant between-group differences were observed for hip extension with flexed knee ROM in dominant (soccer: 142.43 ± 7.74°; basketball: 148.63 ± 8.10°) and non-dominant (soccer: 144.38 ± 8.36°; basketball: 148.63 ± 6.45°) legs; hip flexion with flexed knee ROM in dominant (soccer: 13.26 ± 4.71°; basketball: 9.96 ± 3.42°) and non-dominant (soccer: 12.86 ± 4.55°; basketball: 9.70 ± 3.62°) legs; and for the ratio of hip abduction (soccer: 1.02 ± 0.08; basketball: 0.97 ± 0.11). However, no significant between-group differences were observed for bilateral and unilateral jump capacity, or for inter-limb asymmetries (dominant vs. non-dominant leg). Finally, no associations were observed between ROM ratio (dominant vs. non-dominant leg) and bilateral jump performance. These findings lead to the suggestion that differences on passive ROM values in young male athletes may be sport-specific. Additionally, there seems to be need for the implementation of training strategies specifically aimed at improving bilateral or unilateral jump ability, or at diminishing inter limb passive ROM differences in order to improve multidirectional jump performance for neither soccer nor basketball youth male players.


Assuntos
Basquetebol/fisiologia , Extremidade Inferior/fisiologia , Amplitude de Movimento Articular , Futebol/fisiologia , Adolescente , Desempenho Atlético , Humanos , Articulações/fisiologia , Masculino , Movimento
17.
Rev. bras. med. esporte ; 27(1): 26-29, Jan.-Mar. 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1156110

RESUMO

ABSTRACT Objective The purpose of this study was to examine arterial stiffness in elite basketball and soccer athletes by pulse wave velocity. Methods The cohort comprised 35 healthy male volunteers aged 17 to 26 years. All the subjects were either basketball players (n=9), soccer players (n=12) or sedentary controls (n=14). Arterial stiffness was measured by the Pulse Trace System (Micro Medical Ltd., Rochester, UK) and echocardiographic images were taken using a commercially available machine (Vivid 7 GE-Vingmed, Horten, Norway) with a 2.5 MHz transducer. Results The basketball players had significantly higher heights and body weights as compared to both the soccer players and the controls. The aortic elastic properties derived from the echocardiographic measurements did not differ between the groups. The peripheral pulse wave velocity measurements showed significantly lower values both in the basketball and soccer players compared to the controls, whereas the central pulse wave velocity measurement was significantly lower only in the basketball players as compared to the controls. No significant difference was seen between the basketball and soccer players. Conclusions The results of this study show that football and basketball exercises comprised of aerobic, anaerobic, endurance balance-coordination and sport-specific training play a role in reducing arterial stiffness. Level of evidence I; type of study: prognostic study.


RESUMO Objetivo O propósito deste estudo foi examinar a rigidez arterial em atletas de basquetebol e futebol medindo a velocidade da onda do pulso. Métodos A coorte foi composta por 35 voluntários saudáveis do sexo masculino, com idade entre 17 a 26 anos. Os participantes eram jogadores de basquetebol (n = 9), jogadores de futebol (n = 12) e controles sedentários (n = 14). A rigidez arterial foi medida com o Pulse Trace System (Micro Medical Ltd., Rochester, Reino Unido) e as imagens ecocardiográficas foram obtidas com um aparelho disponível no mercado, com transdutor de 2,5 MHz (Vivid 7 GE-Vingmed, Horten, Noruega). Resultados Os jogadores de basquetebol tinham estatura e peso corporal consideravelmente superiores aos dos jogadores de futebol e aos controles. As propriedades elásticas aórticas derivadas das medicas ecocardiográficas não diferiram entre os grupos. A velocidade da onda de pulso periférico foi significativamente menor nos jogadores de basquetebol e futebol em comparação com os controles, enquanto os jogadores de basquetebol tiveram velocidade da onda do pulso central consideravelmente menor que os controles. Não se observou diferença significativa entre os jogadores de basquetebol e os de futebol. Conclusões Os resultados deste estudo mostram que os exercícios de treinamento de futebol e basquetebol: aeróbicos, anaeróbicos, de resistência, de coordenação e equilíbrio e os treinamentos específicos de cada esporte têm um papel importante na redução da rigidez arterial. Nível de Evidência I, Estudo prognóstico.


RESUMEN Objetivo El propósito de este estudio fue examinar la rigidez arterial en atletas de básquetbol y fútbol midiendo la velocidad de onda de pulso. Métodos La cohorte fue compuesta por 35 voluntarios saludables del sexo masculino, con edad entre 17 y 26 años. Los participantes eran jugadores de básquetbol (n=9), jugadores de fútbol (n=12) y controles sedentarios (n=14). La rigidez arterial fue medida con Pulse Trace System (Micro Medical Ltd., Rochester, Reino Unido) y las imágenes ecocardiográficas fueron obtenidas con un aparato disponible en el mercado, con transductor de 2,5 MHz (Vivid 7 GE-Vingmed, Horten, Noruega). Resultados Los jugadores de básquetbol tenían estatura y peso corporal considerablemente superiores a los de los jugadores de fútbol y a los de los controles. Las propiedades elásticas aórticas derivadas de las medidas ecocardiográficas no difirieron entre los grupos. La velocidad de onda de pulso periférico fue significativamente menor en los jugadores de básquetbol y fútbol en comparación con los controles, mientras que los jugadores de básquetbol tuvieron velocidad de onda de pulso central considerablemente menor que los controles. No se observó diferencia significativa entre los jugadores de básquetbol y los de fútbol. Conclusiones Los resultados de este estudio muestran que los ejercicios de entrenamiento de fútbol y básquetbol: aeróbicos, anaeróbicos, de resistencia, de coordinación y equilibrio y los entrenamientos específicos de cada deporte tienen un papel importante en la reducción de la rigidez arterial. Nivel de Evidencia I, Estudio pronóstico.


Assuntos
Humanos , Masculino , Adolescente , Adulto , Adulto Jovem , Futebol/fisiologia , Basquetebol/fisiologia , Rigidez Vascular/fisiologia , Análise de Onda de Pulso/métodos , Estudos de Coortes
18.
J Orthop Res ; 39(7): 1512-1522, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32910520

RESUMO

Magnetic resonance imaging (MRI) is commonly used to evaluate the morphology of the knee in athletes with high-knee impact; however, complex repeated loading of the joint can lead to biochemical and structural degeneration that occurs before visible morphological changes. In this study, we utilized multiparametric quantitative MRI to compare morphology and composition of articular cartilage and subchondral bone shape between young athletes with high-knee impact (basketball players; n = 40) and non-knee impact (swimmers; n = 25). We implemented voxel-based relaxometry to register all cases to a single reference space and performed a localized compositional analysis of T 1ρ - and T 2 -relaxation times on a voxel-by-voxel basis. Additionally, statistical shape modeling was employed to extract differences in subchondral bone shape between the two groups. Evaluation of cartilage composition demonstrated a significant prolongation of relaxation times in the medial femoral and tibial compartments and in the posterolateral femur of basketball players in comparison to relaxation times in the same cartilage compartments of swimmers. The compositional analysis also showed depth-dependent differences with prolongation of the superficial layer in basketball players. For subchondral bone shape, three total modes were found to be significantly different between groups and related to the relative sizes of the tibial plateaus, intercondylar eminences, and the curvature and concavity of the patellar lateral facet. In summary, this study identified several characteristics associated with a high-knee impact which may expand our understanding of local degenerative patterns in this population.


Assuntos
Basquetebol/fisiologia , Cartilagem Articular/fisiologia , Articulação do Joelho/fisiologia , Atletas , Cartilagem Articular/diagnóstico por imagem , Estudos Transversais , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Natação/fisiologia , Adulto Jovem
19.
Med Sci Sports Exerc ; 53(5): 945-950, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33148971

RESUMO

PURPOSE: The primary aims of this investigation were to describe the magnitude of asymmetries of common variables during running among healthy athletes and to determine if sex and speed influence magnitudes of asymmetry. METHODS: This study analyzed routinely collected running gait data on healthy Division I collegiate athletes. All athletes had no history of lower extremity surgery, no lower extremity injuries for 3 months before testing, and running data available at 2.68, 2.95, 3.35, 3.80, and 4.47 m·s-1. Asymmetries were calculated for ground reaction forces, spatiotemporal metrics, joint kinematics, and joint kinetics. Separate linear mixed-effects models assessed the influence of sex, speed, and the interaction on asymmetries of interest. z Scores were calculated for significant effects to further assess the magnitude of differences. RESULTS: Results from 204 athletes were included. The magnitude of asymmetry varied depending on the variable of interest, with asymmetries ≤3° observed for joint kinematics and greater asymmetries observed among joint work asymmetries ranging from 10% to 40%. No significant interactions between sex and speed were observed. Differences in sex and speed were noted; however, the effect sizes were very small based on z score comparison (-0.17 ≤ z ≤ 0.36) and were unlikely to be meaningful. CONCLUSIONS: The magnitude of asymmetry varies considerably depending on the running gait variable. Interpretation of between-limb asymmetry in running mechanics needs to be specific to the variable of interest, whereas sex or running speed seem to be minor factors.


Assuntos
Fenômenos Biomecânicos/fisiologia , Marcha/fisiologia , Extremidade Inferior/fisiologia , Corrida/fisiologia , Adolescente , Articulação do Tornozelo/fisiologia , Basquetebol/fisiologia , Desaceleração , Feminino , Análise da Marcha/métodos , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Fatores Sexuais , Futebol/fisiologia , Atletismo/fisiologia , Adulto Jovem
20.
Int J Sports Med ; 42(4): 336-343, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33096577

RESUMO

We sought to examine the relationship between upper-leg compartmental lean mass, muscle-specific strength, and explosive strength following anterior cruciate ligament reconstruction. Twleve adolescent female athletes with prior anterior cruciate ligament reconstruction were individually-matched by age (16.4±0.9 vs. 16.4±1.0 yrs.), body mass index (23.2±2.1 vs. 23.2±2.7 kg/m2), and sport to 12 female athlete controls. One total-body and 2 lateral-leg dual X-ray absorptiometry scans measured total/segmental body composition. Isokinetic dynamometry measured knee extensor/flexor peak torque. Squat jumps on force platforms measured bilateral peak vertical ground reaction force. Paired t-tests assessed lean mass, peak torque, and force between previously-injured athletes' legs and between previously-injured and control athletes' legs. Previously-injured athletes' involved vs. non-involved leg demonstrated lower total (7.13±0.75 vs. 7.43±0.99 kg; p<0.01) and anterior (1.49±0.27 vs. 1.61±0.23 kg; p<0.01) and posterior (1.90±0.19 vs. 2.02±0.21 kg; p=0.04) upper-leg lean mass. Involved leg peak torque (1.36±0.31; 1.06±0.27; 0.97±0.19 Nm/kg) was lower vs. non-involved leg (1.71±0.36; 1.24±0.33; 1.04±0.15 Nm/kg; p<0.01-0.02) for extension at 60 and 120°/sec and flexion at 60°/sec and vs. controls' 'matched' leg (1.77±0.40 Nm/kg; p=0.01) for extension at 60°/sec. Involved leg force (296±45N) was lower vs. non-involved leg (375±55N; p<0.01) and vs. controls' 'matched' leg (372±88N; p=0.02). One-year post-anterior cruciate ligament reconstruction, adolescent female athletes' involved leg demonstrated relative muscle dysfunction.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/efeitos adversos , Músculo Esquelético/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Volta ao Esporte/fisiologia , Absorciometria de Fóton , Adolescente , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Atletas , Basquetebol/fisiologia , Fenômenos Biomecânicos/fisiologia , Composição Corporal , Estudos de Casos e Controles , Intervalos de Confiança , Teste de Esforço/métodos , Feminino , Ginástica/fisiologia , Humanos , Articulação do Joelho/fisiologia , Perna (Membro)/anatomia & histologia , Força Muscular/fisiologia , Esqui/fisiologia , Torque
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